MIAMI ‚Äď A campaign to repeal a local ordinance banning discrimination based on sexual orientation is emerging as a major test in an ongoing national debate over the rights of homosexuals.

Both sides of the debate view the outcome of the Sept. 10 referendum in Miami-Dade County as a potential watershed in competing efforts to either advance or suppress gay rights.

The stakes are also high here because Miami is under active consideration as a site for both the Democratic and Republican national conventions in 2004. And local business leaders are worried that the controversy could hurt South Florida's economy.

The campaign has been anything but mundane, with no shortage of mud to sling. In recent weeks, the president of the Miami-Dade Christian Coalition and three other repeal workers have been arrested on charges that they fraudulently collected signatures in the repeal petition drive....